Sleep disturbances are very common in the elderly. As many as 40% of older adults complain about sleep problems, including inability to fall asleep quickly, frequent nocturnal awakenings, or early morning awakenings. Untreated sleep disturbances may increase the risk for depression and early mortality. Older adults frequently use prescription hypnotic and over-the-counter medications as sleep aids, despite observations these drugs further disrupt sleep patterns and have untoward side effects. Herbal medicines as dietary supplements are already quite popular and likely to be used by increasing numbers of adults in the next few decades. Alternative herbal medicines, such as valerian, which was in the top 20 best selling herbal products in the United States in 2001, have the potential to enhance sleep but their efficacy needs to be established in older adults. Valerian contains a variety of compounds including valerenic acid and its derivatives. The pharmacokinetic properties of the valerian constituents have not been reported and there is nothing known about the pharmacokinetic properties of valerian constituents in relation to objective sleep measures. A limited literature of small-sample placebo-controlled trials suggests that valerian may improve sleep and has a very low rate of side effects. The specific aims of this preliminary study are to determine the sleep enhancing effects of a recommended dose of valerian and to describe its pharmacokinetic properties in older adults with a complaint of sleep disturbance. We have developed an assay for valerenic acid and will describe the pharmacokinetics of valerian after a single dose and at steady state following two weeks of continuous treatment and relate the sleep enhancing effects as shown by polysomnography to valerian PK. Our working hypothesis is that valerian will enhance sleep after two weeks of daily nighttime dosing (chronic), but is not likely to enhance sleep after a single dose (acute). The design will be a single group, double-blind, placebo controlled cross-over trial in 20 relatively healthy older adult women and men, 55 to 80 years old. We expect the study outcomes will provide preliminary data in support of a large randomized clinical trial of valerian effects on subjective and objective sleep quality in older adults.